Association between alcohol consumption and incidence of impaired insulin secretion and insulin resistance in Japanese: The Saku study

Aims To investigate the effect of alcohol consumption on impaired insulin secretion and insulin resistance in Japanese. Methods The participants in this 5-year cohort study were 2100 Japanese aged 30–74 years without type 2 diabetes mellitus, impaired insulin secretion, or insulin resistance who underwent a medical checkup including 75-g OGTT between April 2008 and March 2009 at Saku Central Hospital. Alcohol consumption was categorized as follows: non-drinker (0 g/week), light drinker (1–139 g/week in men and 1–69 g/week in women), moderate drinker (140–274 g/week in men and 70–139 g/week in women) and heavy drinker (≥275 g/week in men and ≥140 g/week in women). The hazard ratios (HRs) and 95% CIs among light to heavy drinkers for incidence of impaired insulin secretion (insulinogenic index ≤51.7) and insulin resistance (HOMA-IR ≥ 2.5), detected by an OGTT at the time of a follow-up medical checkup before the end of March 2014, were estimated by multivariable adjusted Cox proportional hazard models as reference values for non-drinkers. Results There were 708 cases of impaired insulin secretion and 191 cases of insulin resistance. The HRs (95% CIs) for impaired insulin secretion in light, moderate and heavy drinkers were 1.16 (0.96–1.40), 1.35 (1.07–1.70) and 1.64 (1.24–2.16), respectively (P for trend <0.001). For insulin resistance, the HRs were 1.22 (0.84–1.76), 1.42 (0.91–2.22) and 1.59 (0.96–2.65), respectively (P for trend = 0.044). Conclusion Alcohol consumption was positively associated with the incidence of both impaired insulin secretion and insulin resistance.